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1.
Br J Haematol ; 204(2): 638-643, 2024 02.
Article in English | MEDLINE | ID: mdl-37571963

ABSTRACT

Immune thrombotic thrombocytopenic purpura (iTTP) is a rare and life-threatening haematological condition. Initial treatment involves plasma exchange (PLEX), corticosteroids, caplacizumab and rituximab. In relapsed and refractory cases despite initial treatments, further immune-modulating therapy includes the proteasome inhibitor, bortezomib. Evidence for bortezomib in this setting is limited to case reports and case series. We report our experience and perform a systematic review of the literature. We identified 21 publications with 28 unique patients in addition to our cohort of eight patients treated with bortezomib. The median age of patients was 44 years (IQR: 27-53) and 69% female. They were usually in an initial, refractory presentation of iTTP where they had received PLEX, corticosteroids, rituximab and another line of therapy. After bortezomib administration, 72% of patients had a complete response, with 85% maintaining a durable response without relapse at the last follow-up.


Subject(s)
Purpura, Thrombocytopenic, Idiopathic , Purpura, Thrombotic Thrombocytopenic , Humans , Female , Adult , Middle Aged , Male , Bortezomib , Rituximab , Retrospective Studies , Purpura, Thrombocytopenic, Idiopathic/therapy , Adrenal Cortex Hormones , Plasma Exchange , ADAMTS13 Protein
2.
Bioconjug Chem ; 29(7): 2225-2231, 2018 07 18.
Article in English | MEDLINE | ID: mdl-29894633

ABSTRACT

Polymeric nanoparticles (NPs) represent one of the most promising tools in nanomedicine and have been extensively studied for the delivery of water-insoluble drugs. However, the efficient loading of therapeutic enzymes and proteins in polymer-based nanostructures remains an open challenge. Here, we report a synthesis method for a new enzyme delivery system based on cross-linked enzyme aggregates (CLEAs) encapsulation into poly(lactide- co-glycolide) (PLGA) NPs. We tested the encapsulation strategy on four enzymes currently investigated for enzyme replacement therapy: palmitoyl protein thioesterase 1 (PPT1; defective in NCL1 disease), galactosylceramidase (GALC; defective in globoid cell leukodystrophy), alpha glucosidase (aGLU; defective in Pompe disease), and beta glucosidase (bGLU; defective in Gaucher's disease). We demonstrated that our system allows encapsulation of enzymes with excellent activity retention (usually around 60%), thus leading to functional and targeted nanostructures suitable for enzyme delivery. We then demonstrated that CLEA NPs efficiently deliver PPT1 in cultured cells, with almost complete enzyme release occurring in 48 h. Finally, we demonstrated that enzymatic activity is fully recovered in primary NCL1 fibroblasts upon treatment with PPT1 CLEA NPs.


Subject(s)
Drug Carriers/chemistry , Enzymes/administration & dosage , Nanoparticles/chemistry , Polymers/therapeutic use , Cells, Cultured , Fibroblasts/metabolism , Galactosylceramidase/administration & dosage , Humans , Methods , Polylactic Acid-Polyglycolic Acid Copolymer/therapeutic use , Solubility , Thiolester Hydrolases/administration & dosage , alpha-Glucosidases/administration & dosage , beta-Glucosidase/administration & dosage
3.
Biochim Biophys Acta ; 1852(10 Pt B): 2292-300, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25957554

ABSTRACT

The neuronal ceroid lipofuscinoses represent a group of severe childhood lysosomal storage diseases. With at least 13 identified variants they are the most common cause of inherited neurodegeneration in children. These diseases share common pathological characteristics including motor problems, vision loss, seizures, and cognitive decline, culminating in premature death. Currently, no form of the disease can be treated or cured, with only palliative care to minimise discomfort. This review focuses on current and potentially ground-breaking clinical trials, including small molecule, enzyme replacement, stem cell, and gene therapies, in the development of effective treatments for the various disease subtypes. This article is part of a Special Issue entitled: "Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)".

4.
Mol Genet Metab ; 117(2): 210-6, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26597320

ABSTRACT

Infantile neuronal ceroid lipofuscinosis (INCL, Infantile Batten disease) is an invariably fatal neurodegenerative pediatric disorder caused by an inherited mutation in the PPT1 gene. Patients with INCL lack the lysosomal enzyme palmitoyl protein thioesterase-1 (PPT1, EC 3.1.2.22), resulting in intracellular accumulation of autofluorescent storage material and subsequent neuropathology. The Ppt1(-/-) mouse is deficient in PPT1 activity and represents a useful animal model of INCL that recapitulates most of the clinical and pathological aspects of the disease. Preclinical therapeutic experiments performed in the INCL mouse include CNS-directed gene therapy and recombinant enzyme replacement therapy; both seek to re-establish therapeutic levels of the deficient enzyme. We present a novel method for the histochemical localization of PPT1 activity in the Ppt1(-/-) mouse. By utilizing the substrate CUS-9235, tissues known to be positive for PPT1 activity turn varying intensities of blue. Presented here are histochemistry data showing the staining pattern in Ppt1(-/-), wild type, and Ppt1(-/-) mice treated with enzyme replacement therapy or AAV2/9-PPT1-mediated gene therapy. Results are paired with quantitative biochemistry data that confirm the ability of CUS-9235 to detect and localize PPT1 activity. This new method complements the current tools for the study of INCL and evaluation of effective therapies.


Subject(s)
Thiolester Hydrolases/metabolism , Animals , Female , Genetic Therapy , Humans , Kidney/enzymology , Liver/enzymology , Male , Mice, Knockout , Myocardium/enzymology , Neuronal Ceroid-Lipofuscinoses/therapy , Organ Specificity , Thiolester Hydrolases/genetics
5.
Transfus Apher Sci ; 55(3): 364-367, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27776919

ABSTRACT

Thrombosis is known to occur in patients with rare inherited bleeding disorders, usually in the presence of a thrombotic risk factor such as surgery and/or factor replacement therapy, but sometimes spontaneously. We present the case of a 72-year-old African American male diagnosed with congenital factor VII (FVII) deficiency after presenting with ischemic stroke, presumably embolic, in the setting of atherosclerotic carotid artery stenosis. The patient had an international normalized ratio (INR) of 2.0 at presentation, with FVII activity of 6% and normal Extem clotting time in rotational thromboelastometry. He was treated with aspirin (325 mg daily) and clopidogrel (75 mg daily) with no additional bleeding or thrombotic complications throughout his admission. This case provides further evidence that moderate to severe FVII deficiency does not protect against thrombosis.


Subject(s)
Brain Ischemia/drug therapy , Factor VII Deficiency/complications , Factor VII Deficiency/genetics , Inheritance Patterns/genetics , Stroke/complications , Aged , Blood Coagulation Tests , Brain Ischemia/complications , Factor VII Deficiency/drug therapy , Humans , Male , Stroke/drug therapy
6.
Mol Genet Metab ; 116(1-2): 98-105, 2015.
Article in English | MEDLINE | ID: mdl-25982063

ABSTRACT

The neuronal ceroid lipofuscinoses (NCLs) are a group of related hereditary lysosomal storage disorders characterized by progressive loss of neurons in the central nervous system resulting in dementia, loss of motor skills, seizures and blindness. A characteristic intralysosomal accumulation of autofluorescent storage material occurs in the brain and other tissues. Three major forms and nearly a dozen minor forms of NCL are recognized. Infantile-onset NCL (CLN1 disease) is caused by severe deficiency in a soluble lysosomal enzyme, palmitoyl-protein thioesterase-1 (PPT1) and no therapy beyond supportive care is available. Homozygous Ppt1 knockout mice reproduce the known features of the disease, developing signs of motor dysfunction at 5 months of age and death around 8 months. Direct delivery of lysosomal enzymes to the cerebrospinal fluid is an approach that has gained traction in small and large animal models of several other neuropathic lysosomal storage diseases, and has advanced to clinical trials. In the current study, Ppt1 knockout mice were treated with purified recombinant human PPT1 enzyme delivered to the lumbar intrathecal space on each of three consecutive days at 6 weeks of age. Untreated PPT1 knockout mice and wild-type mice served as additional controls. Four enzyme concentration levels (0, 2.6, 5.3 and 10.6 mg/ml of specific activity 20 U/mg) were administered in a volume of 80 Āµl infused over 8 min. Each group consisted of 16-20 mice. The treatment was well tolerated. Disease-specific survival was 233, 267, 272, and 284days for each of the four treatment groups, respectively, and the effect of treatment was highly significant (p<0.0001). The timing of motor deterioration was also delayed. Neuropathology was improved as evidenced by decreased autofluorescent storage material in the spinal cord and a decrease in CD68 staining in the cortex and spinal cord. The improvements in motor function and survival are similar to results reported for preclinical studies involving other lysosomal storage disorders, such as CLN2/TPP1 deficiency, for which intraventricular ERT is being offered in clinical trials. If ERT delivery to the CSF proves to be efficacious in these disorders, PPT1 deficiency may also be amenable to this approach.


Subject(s)
Disease Models, Animal , Enzyme Replacement Therapy , Membrane Proteins/therapeutic use , Motion , Neuronal Ceroid-Lipofuscinoses/drug therapy , Animals , Brain/drug effects , Brain/immunology , Brain/pathology , Disease-Free Survival , Dose-Response Relationship, Drug , Humans , Injections, Spinal , Membrane Proteins/pharmacology , Mice, Inbred C57BL , Mice, Knockout , Recombinant Proteins/pharmacology , Recombinant Proteins/therapeutic use , Thiolester Hydrolases/genetics , Tripeptidyl-Peptidase 1
7.
J Biol Chem ; 287(1): 523-530, 2012 Jan 02.
Article in English | MEDLINE | ID: mdl-22081607

ABSTRACT

Post-translational palmitoylation of intracellular proteins is mediated by protein palmitoyltransferases belonging to the DHHC family, which share a common catalytic Asp-His-His-Cys (DHHC) motif. Several members have been implicated in neuronal development, neurotransmission, and synaptic plasticity. We previously observed that mice homozygous for a hypomorphic allele of the ZDHHC5 gene are impaired in context-dependent learning and memory. To identify potentially relevant protein substrates of DHHC5, we performed a quantitative proteomic analysis of stable isotope-labeled neuronal stem cell cultures from forebrains of normal and DHHC5-GT (gene-trapped) mice using the bioorthogonal palmitate analog 17-octadecynoic acid. We identified Ć¢ĀˆĀ¼300 17-octadecynoic acid-modified and hydroxylamine-sensitive proteins, of which a subset was decreased in abundance in DHHC5-GT cells. Palmitoylation and oligomerization of one of these proteins (flotillin-2) was abolished in DHHC5-GT neuronal stem cells. In COS-1 cells, overexpression of DHHC5 markedly stimulated the palmitoylation of flotillin-2, strongly suggesting a direct enzyme-substrate relationship. Serendipitously, we found that down-regulation of DHHC5 was triggered within minutes following growth factor withdrawal from normal neural stem cells, a maneuver that is used to induce neural differentiation in culture. The effect was reversible for up to 4 h, and degradation was partially prevented by inhibitors of ubiquitin-mediated proteolysis. These findings suggest that protein palmitoylation can be regulated through changes in DHHC PAT levels in response to differentiation signals.


Subject(s)
Cell Differentiation , Lipoylation , Membrane Proteins/metabolism , Neurons/cytology , Neurons/metabolism , Proteolysis , Acyltransferases , Animals , Cells, Cultured , Humans , Membrane Proteins/chemistry , Membrane Proteins/genetics , Mice , Mutagenesis, Site-Directed , Mutation , Neural Stem Cells/cytology , Neural Stem Cells/metabolism , Protein Multimerization , Protein Structure, Quaternary
8.
Gastroenterology ; 140(3): 857-67, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21111738

ABSTRACT

BACKGROUND & AIMS: Mutations in TRPML1, a lysosomal Ca(2+)-permeable TRP channel, lead to mucolipidosis type IV, a neurodegenerative lysosomal storage disease. An unusual feature of mucolipidosis type IV is constitutive achlorhydria. We produced Trpml1(-/-) (null) mice to investigate the requirement for this protein in gastric acid secretion. METHODS: Trpml1-null mice were generated by gene targeting. The expression of Trpml1 and its role in acid secretion by gastric parietal cells were analyzed using biochemical, histologic, and ultrastructural approaches. RESULTS: Trpml1 is expressed by parietal cells and localizes predominantly to the lysosomes; it was dynamically palmitoylated and dephosphorylated in vivo following histamine stimulation of acid secretion. Trpml1-null mice had significant impairments in basal and histamine-stimulated gastric acid secretion and markedly reduced levels of the gastric proton pump. Histologic and ultrastructural analyses revealed that Trpml1(-/-) parietal cells were enlarged, had multivesicular and multi-lamellated lysosomes, and maintained an abnormal intracellular canalicular membrane. The intralysosomal Ca(2+) content and receptor-mediated Ca(2+) signaling were, however, unaffected in Trpml1(-/-) gastric glands, indicating that Trpml1 does not function in the regulation of lysosomal Ca(2+). CONCLUSIONS: Loss of Trpml1 causes reduced levels and mislocalization of the gastric proton pump and alters the secretory canaliculi, causing hypochlorhydria and hypergastrinemia. The lysosomal enlargement and defective intracellular canaliculi formation observed in Trpml1(-/-) parietal cells indicate that Trpml1 functions in the formation and trafficking of the tubulovesicles. This study provides direct evidence for the regulation of gastric acid secretion by a TRP channel; TRPML1 is an important protein in parietal cell apical membrane trafficking.


Subject(s)
Gastric Acid/metabolism , Mucolipidoses/metabolism , Parietal Cells, Gastric/metabolism , TRPM Cation Channels/deficiency , Achlorhydria/genetics , Achlorhydria/metabolism , Achlorhydria/physiopathology , Animals , Calcium/metabolism , Disease Models, Animal , Gastrins/blood , H(+)-K(+)-Exchanging ATPase/metabolism , Histamine/metabolism , Hypertrophy , Lipoylation , Lysosomes/metabolism , Lysosomes/ultrastructure , Mice , Mice, Inbred C57BL , Mice, Knockout , Mucolipidoses/genetics , Mucolipidoses/pathology , Mucolipidoses/physiopathology , Parietal Cells, Gastric/ultrastructure , Phosphorylation , Protein Transport , TRPM Cation Channels/genetics , Time Factors , Transient Receptor Potential Channels
9.
Mol Genet Metab ; 107(1-2): 213-21, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22704978

ABSTRACT

PPT1-related neuronal ceroid lipofuscinosis (NCL) is a lysosomal storage disorder caused by deficiency in a soluble lysosomal enzyme, palmitoyl-protein thioesterase-1 (PPT1). Enzyme replacement therapy (ERT) has not been previously examined in a preclinical animal model. Homozygous PPT1 knockout mice reproduce the known features of the disease, developing signs of motor dysfunction at 5 months of age and death by around 8 months. In the current study, PPT1 knockout mice were treated with purified recombinant PPT1 (0.3 mg, corresponding to 12 mg/kg or 180 U/kg for a 25 g mouse) administered intravenously weekly either 1) from birth; or 2) beginning at 8 weeks of age. The treatment was surprisingly well tolerated and neither anaphylaxis nor antibody formation was observed. In mice treated from birth, survival increased from 236 to 271 days (p<0.001) and the onset of motor deterioration was similarly delayed. In mice treated beginning at 8 weeks, no increases in survival or motor performance were seen. An improvement in neuropathology in the thalamus was seen at 3 months in mice treated from birth, and although this improvement persisted it was attenuated by 7 months. Outside the central nervous system, substantial clearance of autofluorescent storage material in many tissues was observed. Macrophages in spleen, liver and intestine were especially markedly improved, as were acinar cells of the pancreas and tubular cells of the kidney. These findings suggest that ERT may be an option for addressing visceral storage as part of a comprehensive approach to PPT1-related NCL, but more effective delivery methods to target the brain are needed.


Subject(s)
Enzyme Replacement Therapy , Neuronal Ceroid-Lipofuscinoses/drug therapy , Neuronal Ceroid-Lipofuscinoses/mortality , Recombinant Proteins/administration & dosage , Thiolester Hydrolases/administration & dosage , Animals , Brain/metabolism , Brain/pathology , Disease Models, Animal , Female , Humans , Lysosomes/drug effects , Lysosomes/metabolism , Male , Mice , Mice, Knockout , Motor Activity/drug effects , Rotarod Performance Test , Thiolester Hydrolases/adverse effects , Viscera/drug effects , Viscera/metabolism , Viscera/pathology
10.
J Clin Invest ; 132(20)2022 10 17.
Article in English | MEDLINE | ID: mdl-36040802

ABSTRACT

CLN1 disease, also called infantile neuronal ceroid lipofuscinosis (NCL) or infantile Batten disease, is a fatal neurodegenerative lysosomal storage disorder resulting from mutations in the CLN1 gene encoding the soluble lysosomal enzyme palmitoyl-protein thioesterase 1 (PPT1). Therapies for CLN1 disease have proven challenging because of the aggressive disease course and the need to treat widespread areas of the brain and spinal cord. Indeed, gene therapy has proven less effective for CLN1 disease than for other similar lysosomal enzyme deficiencies. We therefore tested the efficacy of enzyme replacement therapy (ERT) by administering monthly infusions of recombinant human PPT1 (rhPPT1) to PPT1-deficient mice (Cln1-/-) and CLN1R151X sheep to assess how to potentially scale up for translation. In Cln1-/- mice, intracerebrovascular (i.c.v.) rhPPT1 delivery was the most effective route of administration, resulting in therapeutically relevant CNS levels of PPT1 activity. rhPPT1-treated mice had improved motor function, reduced disease-associated pathology, and diminished neuronal loss. In CLN1R151X sheep, i.c.v. infusions resulted in widespread rhPPT1 distribution and positive treatment effects measured by quantitative structural MRI and neuropathology. This study demonstrates the feasibility and therapeutic efficacy of i.c.v. rhPPT1 ERT. These findings represent a key step toward clinical testing of ERT in children with CLN1 disease and highlight the importance of a cross-species approach to developing a successful treatment strategy.


Subject(s)
Neuronal Ceroid-Lipofuscinoses , Animals , Child , Disease Models, Animal , Enzyme Replacement Therapy , Humans , Mice , Mutation , Neuronal Ceroid-Lipofuscinoses/drug therapy , Neuronal Ceroid-Lipofuscinoses/genetics , Sheep
11.
J Biol Chem ; 285(17): 13022-31, 2010 Apr 23.
Article in English | MEDLINE | ID: mdl-20178993

ABSTRACT

A family of integral membrane proteins containing a signature DHHC motif has been shown to display protein S-acyltransferase activity, modifying cysteine residues in proteins with fatty acids. The physiological roles of these proteins have largely been unexplored. Here we report that mice homozygous for a hypomorphic allele of a previously uncharacterized member, DHHC5, are born at half the expected rate, and survivors show a marked deficit in contextual fear conditioning, an indicator of defective hippocampal-dependent learning. DHHC5 is highly enriched in a post-synaptic density preparation and co-immunoprecipitates with post-synaptic density protein-95 (PSD-95), an interaction that is mediated through binding of the carboxyl terminus of DHHC5 and the PDZ3 domain of PSD-95. Immunohistochemistry demonstrated that DHHC5 is expressed in the CA3 and dentate gyrus in the hippocampus. These findings point to a previously unsuspected role for DHHC5 in post-synaptic function affecting learning and memory.


Subject(s)
Acyltransferases/biosynthesis , Dentate Gyrus/metabolism , Gene Expression Regulation, Enzymologic/physiology , Intracellular Signaling Peptides and Proteins/metabolism , Membrane Proteins/biosynthesis , Membrane Proteins/metabolism , Memory/physiology , Nerve Tissue Proteins/metabolism , Acyltransferases/genetics , Alleles , Animals , Cell Line , Disks Large Homolog 4 Protein , Female , Guanylate Kinases , Homozygote , Humans , Intracellular Signaling Peptides and Proteins/genetics , Learning/physiology , Male , Membrane Proteins/genetics , Mice , Nerve Tissue Proteins/genetics , PDZ Domains , Rats
12.
Mol Genet Metab ; 99(4): 374-8, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20036592

ABSTRACT

Infantile neuronal ceroid lipofuscinosis (INCL, also known as Haltia-Santavuori disease) is a lysosomal storage disorder of infants and children characterized by blindness, seizures and a progressive neurodegenerative course. Recent clinical trials have involved neural stem cells and gene therapy directed to the central nervous system; however, enzyme replacement therapy has never been addressed. In the current paper, we describe the production of human recombinant PPT1 (the defective enzyme in INCL) by standard methods in Chinese Hamster Ovary (CHO) cells. The enzyme is largely mannose 6-phosphorylated as assessed by mannose 6-phosphate receptor binding (80% bound) and taken up rapidly by immortalized patient lymphoblasts, where clearance of PPT substrates was demonstrated (EC(50) of 0.25 nM after overnight incubation). When injected intravenously into PPT1-deficient mice, the clearance of recombinant human PPT1 from plasma was rapid, with a half-life of 10 min. Most of the injected dose was distributed to the kidney and liver and potentially corrective levels were also observed in heart, lung and spleen. Brain uptake was minimal, as expected based on experience with other intravenously administered lysosomal enzymes. The enzyme may be useful as an adjunct to central nervous system-directed therapies and could be used as a starting point for modifications designed to improve brain delivery.


Subject(s)
Neuronal Ceroid-Lipofuscinoses/therapy , Thiolester Hydrolases/administration & dosage , Animals , Brain/enzymology , CHO Cells , Cricetinae , Cricetulus , Drug Evaluation, Preclinical , Humans , Male , Mice , Mice, Knockout , Recombinant Proteins/administration & dosage , Recombinant Proteins/metabolism , Thiolester Hydrolases/chemistry , Thiolester Hydrolases/metabolism , Tissue Distribution
13.
Mol Genet Metab ; 100(4): 349-56, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20494602

ABSTRACT

The neuronal ceroid lipofuscinoses (NCLs) are lysosomal storage diseases characterized by progressive neurodegeneration and accumulation of autofluorescent storage granules. A 9-month-old Miniature Dachshund presented with NCL-like signs that included disorientation, ataxia, weakness, visual impairment, and behavioral changes. Neurons throughout the CNS contained autofluorescent lysosomal inclusions with granular osmiophilic deposit (GROD) ultrastructure characteristic of classical infantile NCL (INCL). Human INCL is an autosomal recessive disorder that results from mutations in PPT1, a gene that encodes the enzyme palmitoyl protein thioesterase 1 (PPT1; EC 3.1.22). Resequencing of PPT1 from the affected dog revealed that the dog was homozygous for a single nucleotide insertion in exon 8 (PPT1 c.736_737insC), upstream from the His289 active site. Brain tissue from this dog lacked PPT1 activity. The sire and dam of the propositus were heterozygous for the c.736_737insC mutation; whereas, 127 unrelated Dachshunds were homozygous for the wild-type allele. This is the first reported instance of canine NCL caused by a mutation in PPT1.


Subject(s)
Dog Diseases/enzymology , Dog Diseases/genetics , Mutation/genetics , Neuronal Ceroid-Lipofuscinoses/veterinary , Thiolester Hydrolases/genetics , Alleles , Animals , Base Sequence , Brain/pathology , Brain/ultrastructure , DNA Mutational Analysis , DNA, Complementary/genetics , Dogs , Enzyme Assays , Exons/genetics , Fatal Outcome , Male , Microscopy, Fluorescence , Molecular Sequence Data , Neuronal Ceroid-Lipofuscinoses/enzymology , Neuronal Ceroid-Lipofuscinoses/genetics , Retina/pathology , Sequence Alignment
14.
Biochim Biophys Acta ; 1762(10): 920-33, 2006 Oct.
Article in English | MEDLINE | ID: mdl-16839750

ABSTRACT

Neuronal ceroid lipofucinoses (NCLs) are a group of severe neurodegenerative disorders characterized by accumulation of autofluorescent ceroid lipopigment in patients' cells. The different forms of NCL share many similar pathological features but result from mutations in different genes. The genes affected in NCLs encode both soluble and transmembrane proteins and are localized to ER or to the endosomes/lysosomes. Due to selective vulnerability of the central nervous system in the NCL disorders, the corresponding proteins are proposed to have important, tissue specific roles in the brain. The pathological similarities of the different NCLs have led not only to the grouping of these disorders but also to suggestion that the NCL proteins function in the same biological pathway. Despite extensive research, including the development of several model organisms for NCLs and establishment of high-throughput techniques, the precise biological function of many of the NCL proteins has remained elusive. The aim of this review is to summarize the current knowledge of the functions, or proposed functions, of the different NCL proteins.


Subject(s)
Genetic Predisposition to Disease , Mutation , Neuronal Ceroid-Lipofuscinoses/genetics , Aminopeptidases , Animals , Cathepsins/genetics , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases , Endopeptidases/genetics , Humans , Infant , Lysosomal Membrane Proteins , Membrane Glycoproteins/genetics , Membrane Proteins/genetics , Mice , Molecular Chaperones/genetics , Serine Proteases , Thiolester Hydrolases , Tripeptidyl-Peptidase 1
15.
BMC Neurosci ; 8: 95, 2007 Nov 16.
Article in English | MEDLINE | ID: mdl-18021406

ABSTRACT

BACKGROUND: The infantile form of neuronal ceroid lipofuscinosis (also known as infantile Batten disease) is caused by hereditary deficiency of a lysosomal enzyme, palmitoyl-protein thioesterase-1 (PPT1), and is characterized by severe cortical degeneration with blindness and cognitive and motor dysfunction. The PPT1-deficient knockout mouse recapitulates the key features of the disorder, including seizures and death by 7-9 months of age. In the current study, we compared gene expression profiles of whole brain from PPT1 knockout and normal mice at 3, 5 and 8 months of age to identify temporal changes in molecular pathways implicated in disease pathogenesis. RESULTS: A total of 267 genes were significantly (approximately 2-fold) up- or downregulated over the course of the disease. Immediate early genes (Arc, Cyr61, c-fos, jun-b, btg2, NR4A1) were among the first genes upregulated during the presymptomatic period whereas immune response genes dominated at later time points. Chemokine ligands and protease inhibitors were among the most transcriptionally responsive genes. Neuronal survival factors (IGF-1 and CNTF) and a negative regulator of neuronal apoptosis (DAP kinase-1) were upregulated late in the course of the disease. Few genes were downregulated; these included the alpha2 subunit of the GABA-A receptor, a component of cortical and hippocampal neurons, and Hes5, a transcription factor important in neuronal differentiation. CONCLUSION: A molecular description of gene expression changes occurring in the brain throughout the course of neuronal ceroid lipofuscinosis suggests distinct phases of disease progression, provides clues to potential markers of disease activity, and points to new targets for therapy.


Subject(s)
Gene Expression Profiling , Genes, Immediate-Early/physiology , Inflammation/genetics , Neuronal Ceroid-Lipofuscinoses/physiopathology , Up-Regulation/physiology , Algorithms , Animals , Disease Models, Animal , Inflammation/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Neuronal Ceroid-Lipofuscinoses/genetics , Neuronal Ceroid-Lipofuscinoses/pathology , Oligonucleotide Array Sequence Analysis/methods , Thiolester Hydrolases/deficiency , Time Factors
16.
J Investig Med High Impact Case Rep ; 4(1): 2324709616638363, 2016.
Article in English | MEDLINE | ID: mdl-27047980

ABSTRACT

A 70-year-old African American female with a past medical history significant for chronic bilateral shoulder pain and reported sickle cell trait presented with acute-onset bilateral thoracolumbar pain radiating to her left arm. Two days after admission, Hematology was consulted for severely worsening microcytic anemia and thrombocytopenia. Examination of the patient's peripheral blood smear from admission revealed no cell sickling, spherocytes, or schistocytes. Some targeting was noted. A Coombs test was negative. The patient was eventually transferred to the medical intensive care unit in respiratory distress. Hemoglobin electrophoresis confirmed a diagnosis of hemoglobin SC disease. A diagnosis of acute splenic sequestration crisis complicated by acute chest syndrome was crystallized, and red blood cell exchange transfusion was performed. Further research is necessary to fully elucidate the pathophysiology behind acute splenic sequestration crisis, and the role of splenectomy to treat hemoglobin SC disease patients should be better defined.

17.
Biochim Biophys Acta ; 1583(1): 35-44, 2002 Jun 13.
Article in English | MEDLINE | ID: mdl-12069847

ABSTRACT

Fatty acylation of proteins on cysteine residues is a common post-translational modification that plays roles in protein-membrane and protein-protein interactions. Recently, we described a lysosomal palmitoyl-protein thioesterase that removes long-chain fatty acids from lipid-modified cysteine residues in proteins. Deficiency in palmitoyl-protein thioesterase results in a human lysosomal storage disorder, infantile neuronal ceroid lipofuscinosis (INCL), which primarily affects the central nervous system. The pathological hallmark of the disorder is the accumulation of granular osmiophilic deposits (GROD) that resemble lipofuscin, or aging pigment. In previous work, we have shown that [35S]cysteine-labeled lipid thioesters derived from fatty acylated proteins accumulate in cultured cells derived from palmitoyl-protein thioesterase-deficient patients. In the present work, we show that the lipid cysteine thioesters accumulate in the lysosomal fraction, and we further show that the appearance of these compounds in the organic phase is blocked by inhibitors of lysosomal proteolysis, demonstrating through biochemical means the lysosomal nature of the site of palmitoyl-protein thioesterase action. Furthermore, substrates for palmitoyl-protein thioesterase accumulate even in normal cells after leupeptin or chloroquine treatment. This was demonstrated by subjecting extracts of treated cells to exhaustive proteolysis to release protein-bound cysteine lipid for analysis. Cysteamine, a lysosomotropic drug recently proposed for the treatment of INCL, was found to have effects similar to leupeptin and chloroquine, suggesting that its mechanism of action may be more complex than previously understood.


Subject(s)
Chloroquine/pharmacology , Cysteamine/pharmacology , Lysosomes/drug effects , Thiolester Hydrolases/metabolism , Cell Line, Transformed , Chromatography, Thin Layer , Humans , Lysosomes/enzymology , Neuronal Ceroid-Lipofuscinoses/enzymology , Neuronal Ceroid-Lipofuscinoses/pathology
18.
Curr Mol Med ; 2(5): 423-37, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12125808

ABSTRACT

Infantile and classical late infantile neuronal ceroid lipofuscinoses (NCL) are two recent additions to the expanding spectrum of lysosomal storage disorders caused by deficiencies in lysosomal hydrolases. They are latecomers to the lysosomal storage disorders, probably because of the heterogeneous nature of the storage material, which precluded meaningful biochemical analysis. Infantile NCL is caused by deficiency in palmitoyl-protein thioesterase, an enzyme that hydrolyzes fatty acids from cysteine residues in lipid-modified proteins. Classical late-infantile NCL is caused by a deficiency in tripeptidyl amino peptidase-I, a lysosomal peptidase that removes three amino acids from the free amino terminus of peptides or small proteins. Late-onset forms of these disorders have been described. The clinical, biochemical, and molecular genetic aspects of these two latest lysosomal storage disorders are discussed in this review. In addition, approaches to treatment and future directions for research are examined.


Subject(s)
Membrane Proteins/genetics , Neuronal Ceroid-Lipofuscinoses/genetics , Neuronal Ceroid-Lipofuscinoses/pathology , Peptide Hydrolases/genetics , Adolescent , Adult , Age of Onset , Aminopeptidases , Child , Child, Preschool , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases , Endopeptidases , Humans , Infant , Leukocytes/ultrastructure , Microscopy, Electron , Mutation , Neuronal Ceroid-Lipofuscinoses/enzymology , Neuronal Ceroid-Lipofuscinoses/therapy , Polymorphism, Genetic , Serine Proteases , Thiolester Hydrolases , Tripeptidyl-Peptidase 1
19.
Mol Cancer Res ; 13(4): 784-94, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25573953

ABSTRACT

UNLABELLED: Protein S-palmitoylation is a widespread and dynamic posttranslational modification that regulates protein-membrane interactions, protein-protein interactions, and protein stability. A large family of palmitoyl acyl transferases, termed the DHHC family due to the presence of a common catalytic motif, catalyzes S-palmitoylation; the role of these enzymes in cancer is largely unexplored. In this study, an RNAi-based screen targeting all 23 members of the DHHC family was conducted to examine the effects on the growth in non-small cell lung cancer (NSCLC). Interestingly, siRNAs directed against DHHC5 broadly inhibited the growth of multiple NSCLC lines but not normal human bronchial epithelial cell (HBEC) lines. Silencing of DHHC5 by lentivirus-mediated expression of DHHC5 shRNAs dramatically reduced in vitro cell proliferation, colony formation, and cell invasion in a subset of cell lines that were examined in further detail. The phenotypes were restored by transfection of a wild-type DHHC5 plasmid but not by a plasmid expressing a catalytically inactive DHHC5. Tumor xenograft formation was severely inhibited by DHHC5 knockdown and rescued by DHHC5 expression, using both a conventional and tetracycline-inducible shRNA. These data indicate that DHHC5 has oncogenic capacity and contributes to tumor formation in NSCLC, thus representing a potential novel therapeutic target. IMPLICATIONS: Inhibitors of DHHC5 enzyme activity may inhibit non-small cell lung cancer growth.


Subject(s)
Acyltransferases/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Lung Neoplasms/pathology , Membrane Proteins/genetics , Membrane Proteins/metabolism , RNA, Small Interfering/metabolism , Acyltransferases/antagonists & inhibitors , Acyltransferases/genetics , Animals , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Line, Tumor , Cell Movement , Cell Proliferation , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Membrane Proteins/antagonists & inhibitors , Mice , Neoplasm Transplantation
20.
FEBS Lett ; 538(1-3): 207-12, 2003 Mar 13.
Article in English | MEDLINE | ID: mdl-12633880

ABSTRACT

Infantile and juvenile neuronal ceroid lipofuscinosis (NCLs) are progressive neurodegenerative disorders of childhood with distinct ages of clinical onset, but with a similar pathological outcome. Infantile and juvenile NCL are inherited in an autosomal recessive manner due to mutations in the CLN1 and CLN3 genes, respectively. Recently developed Cln1- and Cln3-knockout mouse models share similarities in pathology with the respective human disease. Using oligonucleotide arrays we identified reproducible changes in gene expression in the brains of both 10-week-old Cln1- and Cln3-knockout mice as compared to wild-type controls, and confirmed changes in levels of several of the cognate proteins by immunoblotting. Despite the similarities in pathology, the two mutations affect the expression of different, non-overlapping sets of genes. The possible significance of these changes and the pathological mechanisms underlying NCL diseases are discussed.


Subject(s)
Gene Expression Regulation , Membrane Glycoproteins , Membrane Proteins/physiology , Molecular Chaperones , Neuronal Ceroid-Lipofuscinoses/genetics , Proteins/physiology , Animals , Brain/metabolism , Gene Expression Profiling , Humans , Membrane Proteins/genetics , Mice , Mice, Knockout , Proteins/genetics , Thiolester Hydrolases
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